1. Field of the Invention
This invention relates to tessellating pattern blocks that can be linked to create a variety interesting surface patterns.
2. Prior Art—Two Dimensional Tessellations
A variety of two dimensional tessellating pattern puzzles are known. The simplest examples are traditional jigsaw puzzles, which feature irregularly shaped pieces with graphics. The puzzle pieces tessellate (fit together to fill space) and create continuous patterns when the pieces are correctly assembled. While these puzzles are enjoyable, they tend to stifle creativity; there is only one way to put them together. Concerning one particular edge of one particular puzzle piece, it can only properly abut to one other edge of one other puzzle piece.
Other known tessellating puzzles, whose pieces have more regular geometric shapes, offer more opportunities for creative expression. Although there is still generally one “solution,” pieces of some of these puzzles can be assembled to tessellate in a variety of ways, each of which produces a continuous graphic pattern. However, these pieces with regular geometric shapes are most often still limited in the manner that they can abut with one another. For example, one edge often properly abuts to a fraction of all other edges. Furthermore, although they are interesting, these tessellation puzzles still cannot match the concrete “realness” of a three-dimensional building block. They literally lack a fundamental dimension. A two dimensional tessellation simply does not have the richness and complexity of three dimensional reality.
The reason that makers of two dimensional tessellation puzzles have not made three dimensional puzzles is simply that creating an three dimensional tessellation is very difficult.
Three Dimensional Tessellations
In fact, many common brick-shaped construction blocks do tessellate. Furthermore, they connect releasably. However, these blocks' tessellations are usually limited by the fact that each face can connect most often to one other face. Additionally, most often only two faces of these blocks can form any connection at all. Furthermore, these blocks do not have interesting surface patterns that form continuous patterns with adjacent blocks. If they did have surface patterns, those patterns would always connect to adjacent blocks in the same manner, due to the restrictive nature of their connections.
Some three dimensional tessellation puzzles with surface patterns are known. Whitehurst (U.S. Pat. No. 5,407,201—Apr. 19, 1995) describes a three-dimensional puzzle with individual pieces featuring overlapping “indicia.” These indicia span the edges of juxtaposed pieces. However, since the juxtaposed pieces of Whitehurst's puzzle form only discrete images at their borders, no surprising and interesting patterns can emerge. One can, for example, juxtapose the left and right halves of a pig, but one is still stuck with pigs; it is not possible to arrange the puzzle so something new and unexpected appears. Another shortcoming of Whitehurst's puzzles is that the pieces have no means of connection. They must be supported by a special tray that helps the overall puzzle maintain structural integrity.
Rachovsky (U.S. Pat. No. 6,196,544—Mar. 6, 2001) describes a three-dimensional puzzle whose pieces can be used to create a variety of continuous patterns. Rachovsky's puzzle pieces are identically shaped “z-polycube” pieces featuring different surface patterns. When Rachovsky's puzzle pieces are juxtaposed, banded patterns emerge. By rearranging a plurality of puzzle pieces, one can create a variety of structures with a variety of surface patterns.
Although Rachovsky's puzzle does enable a player to create something new, it has several key disadvantages. First, Rachovsky's puzzle pieces do not securely connect to one another to produce structures with integrity; they must be stacked, nested, or nestled. Second, Rachovsky's puzzle is too difficult and unintuitive to be broadly appealing to the public. His z-shaped puzzle pieces are tricky to manipulate, and his blocks' non-identical surface patterns make play very challenging. A third disadvantage of Rachovsky's puzzle is that his individual puzzle pieces are not inviting in themselves. They are simply not fun looking.
Tessellating Polyhedra with “Six Face Symmetry”
Several U.S. Patents (U.S. Pat. No. 5,098,328, by Bierens—Mar. 24, 1992; U.S. Pat. No. 6,439,571, by Wilson—Aug. 27, 2002; and U.S. Pat. No. D359,315, by Tacey—Jun. 13, 1995) describe cube blocks with “six face symmetry.” All of these cubes' faces are identical, allowing any face on one of these cubes to connect with any face on another identical block. Accordingly, these cubes are generally intended to be used as a set of identical blocks which connect together to build structures. These characteristics make these cubes much more intuitive and simpler to use than the “z-polycubes” described by Rachovsky. However, these prior art cubes with “six face symmetry”, as well as other symmetric polyhedral blocks, have several salient disadvantages.
A first disadvantage of known construction polyhedra is that none of their designs can be easily manufactured using injection molding processes. All of them require the manufacture and assembly of many individual pieces. For example, Bierens' patent (referenced above) suggests a method by which his cubes might be manufactured as six separate pieces, which must then be assembled before use. Hollister describes a somewhat similar plan for a tetrahedral building block with symmetrical faces in his U.S. Pat. No. 6,152,797 (Nov. 28, 2000). Hollister's patent showed how his tetrahedron block might be manufactured as four separate triangular faces, plus four separate insertable connectors—eight pieces in all.
A second disadvantage of known “facially symmetric” polyhedra is that, when they are assembled, no new and interesting continuous surface patterns emerge. They are not a pattern puzzle so much as a structural medium. They lack the intriguing bands that are produced by Rachovsky's “z-polycubes,” for example.
A third disadvantage of the known “facially symmetric” cubes is that their individual appearances are purely functional, not fun. They are geometric structures whose purpose is apparent, but who are not inviting or entertaining in and of themselves.